Stern structure for ships



May S9 H934 M. J. HANLON 958,3 02

STERN STRUCTURE FOR SHIPS Filed may 2o, 1932 4 sheets-sheet l May 8, 3934. M, J, HANLQN ,958,302

STERN STRUCTURE FOR SHIPS Filed May 20, 1952 4 Sheets-Sheet 2 ATTORNEY Mw @y 3934 M. J. HANLON STERN STRUCTURE FOR SHIPS Filed May 20, 1932 4 Sheets-Shea?. 5

WTNESSES ZW @wg/m May w34., M. J. HANLQN STERN STRUCTURE FOR SHIPS Filed May 20. 1932 di Sheets-Sheet 4 NVE T gdm/f im @w1/ray ATTORNEY wnNEssEs Mq/M657@ yatented May 8, 1934 UNITED STATES STERN STRUCTURE FOR SHIPS Michael J. Hanlon, Weehawken, N. J., assignor to Black Diamond Steamship Corporation, New York, N. Y., a corporation of Delaware Application May 20, 1932, Serial No. 612,597 is claims. (ci: 11i-.57)

lThis invention relates to a stern structure for marine vessels, and particularly to those of the larger sized power driven type having a'submerged propeller.

The present invention comprehends an improved stern structure for vessels of the-indicated character, which is applicable to either new constructions or for the remodeling of the stern of previously built ships, especially where the old design is particularly inemcient and remodeling thereof will accomplish a marked improvement in the propulsive efficiency of the vessel and a decrease in the power required for propulsion, also a large reduction in the hull resistance. 4

One of the principal'and outstanding objects or the present inventionv resides in so shaping the stern frame as to minimize the hull suction disturbance and hull resistance and to locate the propeller with reference to a stern frame`so shaped, whereby said propeller is .disposed substantially at the locus of intersection of the after end of the vertical waterplane flow lines which are developed by the vessel when traveling at its normal running speed and at a point where its thrust will be exerted in the more solid water and as rar removed from the influence of the hull suction `disturbances as is possible and practical, so 'as' to obtain the maximum of propulsive efficiency.

As a further feature, the invention comprehends the relative positioning of the propeller and rudder wherein the jet or Wake of the propeller is intersected and cut by the rudder, thereby depriving said jet or wake of the greater proportion of its rotary or swirling motion and causing it to move in an approximately straight direction, resulting in a reactive thrust on or resistance to the'propeller blades so that it becomes a component of and augments the propeller thrust.

The invention further embodies the imparting of a shaping or configuration to the upper portion of the stern frame so as to not only minimize the hull suction disturbance and resistance at this region but, further, to afford a more ecient speedlength ratio While providing accommodation within the confines thereof, for a rudder post or shaft oi' ample diameter and sufficient strength to withstand the rigors of the stresses and strains to which it is subjected.

As a still further object, the invention contemplates a stern frame structure which includes upper and lower fabricated sections which may be cast or `otherwise produced and assembled when embodied in the vessel, and in which the section thereof which accommodates the tail shaft of the propeller is so contoured as to accommodate and house the tail shaft while at the same time affording the proper streamlining to 30 avoid undue resistance and disturbance in the region of the propeller.

A further feature of the invention resides in the provision of an improved rudder post and mounting therefor, by virtue of which the strength of the rudder, its post and mounting are substantially increased, and by virtue of which the maneuvering of the ship is greatly facilitated.

With the above recited and other objects in 7o view, reference is had to the following description and accompanying drawings, in which there is exhibited one example or embodiment of the invention, while the claims denne the actual scope of the same.

In the drawings:

Figure l is a fragmentary vertical section of an improved stern structure.

Figure 2 is a fragmentary horizontal section taken approximately on the line 2--2 of Figure 1. so

Figure 3 is afragmentary horizontal sectional view taken approximately on the line 3-3 of Figure 1.

Figure i is a sectional plan viewcf the upper stern frame section prior to its incorporation g5 in the ship.

Figure 5 is a sectional plan View on a slightly reduced scale taken approximately on the line' indicated at 5 5 in Figure 1.

Figure 6 is a vertical sectional view taken ap- 90 proximately on the line 6-6 of Figure 1,

Figure '7 is a fragmentary vertical sectional view taken approximately on the line '7 7 of Figure 1.

Figure 8 is a similar view taken approximately on the line 8--8 of Figure 1.

Figure 9 is a similar view taken approximately on the line 9--9 of Figure 1.

Figure 10 is a diagrammatic side view illustrating in full and dotted lines a comparative View of the new stern structure superimposed on an old type of stern structure.

Referring to the drawings by characters of reference, the stern structure includes a stern frame consisting of a lower section A and an upper section B, which sections are preferably cast. The section A includes a vertical leg 15 which is of substantially channel shaped cross sectional conguration having forwardly diverging marginal anges 16, the outer surfaces of which flanges, together with the main portion of said leg, de-

pulsive co-efllcient as well as decreases hull resistance at this region. The leg 15 intermediate its lupper and lower ends is shaped to provide a boss 19 for accommodating therethrough the propeller tail shaft 20, its aft bearings 2l, the stern tube 22, etc. Theportion of the leg 15 below the boss 19 is substantially vertical, while the portion of said leg above the boss is inclined rearwardly and upwardly whereby the sharp edge or apex 18 thereof substantially parallels the path 20 of rotation of the forward edge 24 of the propeller blades 25. The upper end of the main portion of the leg 15 is formed with a forwardly directed assembling flange 26 which bridges the forwardly diverging marginal side flanges 16. The lower section A of the stern frame is further provided at its lower end with a forwardly directed substantially horizontal leg 27 of channel shaped cross sectional configuration having upwardly extending marginal side flanges 28 and provided 30 with transverse ribs 29, which in addition to lend- 40 the ing strength to the structure affords means for attaching the floors or elements 30 to the stern frame. The side flanges 28 terminate short of .the forward end 31 of the leg 27 and the lower ksurface of the leg 28 adjacent the forward end 31 is rabbeted as at 32 to accommodate the box keel plate 33 of the hull structure and to provide a flush fit. The remaining lower outer surface .34 is inclined upwardly and rearwardly as shown, purpose of which is to avoid damage to the stern frame in event of grounding of the vessel. The upper stern frame section B consists of an intermediate rearwardly and upwardly inclined Aportion which is of channel shaped cross secr tional configuration formed with upwardly directed side flanges 41 joined by transverse ribs 42 bridging the side flanges to strengthen the frame structure and to afford means for anchoring the floors or elements 43 thereto. The intermediate -portion 40 presents a rearwardly and upwardly inclined lower surface 44, and said portion is further provided at its forward end with a downwardly curved terminal 45 having side flanges 46 and a transverse rib 47 having an angular vers'tically disposed terminal 48 for attachment to one of the elements 43. The portion 40 and its terminal 45 are further developed within the channel to provide arched shaped strengthening webs 49. iThe upper stern frame section B includes an up- -standing portion 50 carried by the intermediate portion'40 at its rear end. The portion 50 is also of channel shaped cross sectional configuration and is provided with forwardly directed side flanges 51 connected and braced by-transverse ribs 52. The portion 50 has a rear edge 53 developed into a compound curve, the convex lower portion of which merges into the concave upper portion thereof, and the upper extremity of said ,v rear edge is rabbeted as at 54 to accommodate 'and provide a flush joint where the curved plates 55 are attached. The portion 40 intermediate its length is formed with an upstanding vertical boss 56 to accommodate the rudder post 57 and its lower bearing 58. 'I'he forward terminal 45 -of the portion 40 is formed with an assembly flange 59 and the lower end of the terminal and flange 59 are designed to abut with the upper end of the vertical leg of the lower section A and its assembly flange 26 to receive the bolts or other equivalent fastening devices 60.

A rudder post trunk 61 is mounted, attached and directly supported on the upper end of the bearing boss 56, and said trunk in turnsupports at its upper end the rudder carrier 62, whereby the entire weight of the rudder and post is transmitted directly to the heavy stern frame while a portion of the bending stress is taken by the trunk and rudder carrier. The rudder post trunk 6l and the bearing boss 56 also function to provide a rigid support for the rudder carrier deck 63. The trunk 61 and boss 56 are provided with lateral flanges 64 for anchorage to the floors or elements 43 so as to eflectually tie and brace the comparatively thin streamlined hull plating sections 65. The boss 56 and trunk 6l provide a watertight chamber which excludes water from the interior of the hull.

A spade type rudder C is carried by the rudder post, and the upper portion of the rudder frame 68 is formed with a downwardly tapered socket 69 for the reception of the correspondingly tapered portion 70 of the rudder post 57, which portion 70 is keyed at 71 and is drawn into-intimate contact with the socket and maintained in place by a nut 72 screwed on the threaded terminal 73 of the depending extension 74 of the rudder post which protrudes through an opening 75 in the rudder frame 68. The nut and threaded terminal are accommodated in the space 76 formed by a transverse opening in the rudder frame, which opening or space is closed by the rudder plating 77. The rudder frame extends downwardly from the top of the rudder to a point below the horizontal center, and the opening or bore 75 is located at the center pressure ci the rudder. The rudder is so developed with its plating as to define a cross sectionally horizontal streamlined configuration in which the axis is disposed at a point approximately one-third of the breadth of the rudder measured from its forward or leading edge 78. The forward and after edges 79 and 80 of the rudder, as well as the opposite face, converge downwardly to effect a decrease in rudder resistance and to provide rudder area which is proportioned to the draft and displacement of the vessel.

The propeller, which is designated generally by the reference character D, is located at a point approximating the locus of intersection of the after end of the waterplane lines on a horizontal plane through the center of the propeller shaft, those waterplane lines being indicated at E in Figure 5 and the locus of intersection being desighated. by the reference character F. In practice, the waterplane lines developed by the forward motion of the ship when the same attains its normal running speed, are disposed vertically and are swept rearwardly by the hull and lag behind the hull. These vertical rearwardly diverging waterplane flow lines which are developed by the contouring of the aft portion of the hull and stern frame in the region are designed for a definite purpose. The objects and advantages obtained from the contouring of the stern frame and adjacent hull surfaces above and below the propeller, combined with the location of the propeller with reference thereto, are the production of ideal water flow conditions to the orbit of the propeller whereby the suction disturbance, as well as the thrust 'deduction factor, is reduced to a minimum, thus insuring maximum propulsion eiliciency. The propeller jet or wake developed by the aforementioned location of the propeller and the contouring of the stern frame and adjacent hull structure eects a divergenceof the water iiow which is designated by the dotted lines G in Figure 5. These ow lines strike the rudder nose at a tangent forwardof the axis of the rudder and thereby intersect the propeller jet, minimizing the. rotary motion of the jet and constraining it to move in a straight line, thus providing more solid water in the orbit of -the propeller, resulting in a reactive effect on the blades, thus improving propulsion efficiency. An advantage is also gained in steering eiciency due to the fact that the rudder is working in a dense jet of high velocity immediately after it leaves the propeller blades. Consequently, a less amount of rudder angle will he required to maintain the vessel on its course and to maneuver the same. Less power for steering gear will be required and,

consequently, less torque will be developed in the rudder post, resulting in less wear and tear on the steering engine and rudder parts and a diminution of maintenance cost. The included angle of the lines G tangent to the rudder nose is equal to the included angle of the lines E developed by the formation of the stern frame and hull plating adjacent the propeller.

What is claimed is:

l. In a marine vessel of the character set forth, a cast stern frame to which the hull plating is attached, said frame including in combination upper and lower sections joined together, the

. lower section of which includes a vertical leg leg externally rabbeted to accommodate the box keel plate.

2. In a marine vessel of the character set forth, a stern frame including in combination upper and lower sections joined together, the lower section of which includes a vertical leg having rearwardly convergent side faces and an enlarged intermediate boss for accommodating the tail shaft of a propeller, said propeller section further including a forwardly directed horizontalA leg externally v rabbeted to accommodate the box keel plate and having transverse strengthening ribs affording means for attaching the oors thereto.

3. In a marine vessel of the character set forth, a stern frame including in combination upper and lower sections joined together, the lower section of which includes a vertical leg having rearwardly convergent side faces and an enlarged intermediate boss for accommodating the tail shaft of a propeller, said propeller section further including a forwardly directed horizontal leg externally rabbeted to accommodate the box keel plate, said legs being of cross sectional channel shape providing side flanges to which the hull plating is attached.

fl. In a marine vessel of the character set forth, a cast stern frame to which the hull plating is attached, said frame including in combination upper and lower cross sectionally channel shaped sections, the upper end of the lower section and the lower end of the upper section having rearwardly directed horizontally disposed mating assembling flanges apertured to receive therethrough connecting means, the lower section including a -vertical leg having rearwardly converging side faces and an enlarged intermediate boss for accommodating the tall shaft of a propeller.

5. In a marine vessel of the character set forth,'

a cast stern frame to which the hull plating is attached, said frame includingb in combination upper and lower cross sectionally channel shaped sections, the upper end of the lower section and the lower end of the upper section having rearwardly directed horizontally disposed mating assembling flanges apertured to receive therethrough connecting means, the lower section including a vertical leg having rearwardly converging side faces and an enlarged intermediate boss for accommodating the tail shaft of a propeller, the portion of the rear edge of the vertical leg above the boss inclining upwardly and rearwardly and disposed substantially parallel to the path of rotation of the forward edges of the blades of the propeller.

6. A stern structure for marine vessels of the character set forth including rearwardly convergent sides in the region of the propeller and a screw propeller located adjacent the locus of intersection of the after end of the vertical waterplane lines developed by the ship when traveling at its normal running speed and a rudder spaced rearwardly of the propeller and against the nose of which rudder said developed divergent waterplane lines aft of the locus of intersection, impinge at a tangent.

7. A stern structure for marine vessels of the character set forth including a submerged screw propeller and a stern frame so constructed and arranged in the region of the propeller and with reference to which region the propeller is so located as to develop, when the ship is traveling at its normal running speed, rearwardly converging vertical waterplane fiow lines, the locus of intersection of 'the after ends of which flow lines are disposed at the fore and aft center of the propeller.

8. A stern structure for marine vessels of the character set forth including a submerged screw propeller and a stern frame so constructed and arranged in the region of the propeller and with reference to which region the propeller is so located as to develop, when the ship is traveling at its normal running speed, rearwardly converging vertical waterplane flow lines, the locus of intersection of the after ends of which flow lines are disposed at the fore and aft center of the propeller and a streamlined rudder mounted in rear of the propeller and so located that the divergent waterplane lines in rear of the locus of intersection developed by the vessel when traveling at a normal running speed, impinge at a tangent to and upon the opposite sides of the nose of the rudder.

9. In a stern structure for marine vessels of the character set forth, a stern frame including an upper cross sectionally channel shaped section comprising an intermediate rearwardly and upwardly inclined portion, a downwardly directed terminal at the forward end of said intermediate portion and an upstanding portion at the aft end of said intermediate portion, the rear edge of which upstanding portion defines a convex lower part and a concave upper part, an integral upstanding hollow rudder post boss formed on the intermediate portion between its forward and rear ends and a horizontal forwardly extending apertured assembling ange at the lower end of the downwardly directed forward terminal.

l0. In a stern structure for marine vessels of the character set forth, a stern frame including an upper cross sectionally channel shaped section comprising an intermediate rearwardly and upwardly inclined portion, a downwardly directed terminal at the forward end of said intermediate portion and an upstanding portion at the aft end of said intermediate portion, the rear edge of which upstanding portion defines a convex lower part and a concave upper part, an integral upstanding hollow rudder post boss formed on the intermediate portion between its forward and rear ends and a tubular rudder post trunk secured to the upper end of the rudder post boss.

11. In a stern structure for marine vessels of the character set forth, a stern frame including an upper cross sectionally channel shaped section comprising an intermediate rearwardly and upwardly inclined portion, a downwardly directed terminal at the forward end of said intermediate portion and an upsta-nding portion at the aft end of said intermediate portion, the rear edge of which upstanding portion defines a convex lower part and a concave upper part, an integral upstanding hollow rudder post boss formed on the intermediate portion between its forward and rear ends, a tubular rudder post trunk secured to the upper end of the rudder post boss and lateral flanges on said trunk for anchorage to the hull plating.

12. In a stern structure for marine vessels of the character set forth, a stern frame including an upper crosssectionally channel shaped section comprising an intermediate rearwardly and upwardly inclined portion, a downwardly directed terminal at the forward end of said intermediate portion and an upstanding portion at the aft end of said intermediate portion, the rear edge of which upstanding portion defines a convex lower part and a concave upper part and a lower section including a vertical leg having at its upper end a horizontal forwardly extending apertured assembly flange mating with the assembly flange of the upper section and connecting means extending through said apertured flanges.

13. In a stern structure for marine vessels of the character set forth, a stern frame including an upper cross sectionally channel shaped section comprising an intermediate rearwardly and upwardly inclined portion, a downwardly directed terminal at the forward end of said intermediate portion and an upstanding portion at the aft end of said intermediate portion, the rear edge of which upstanding portion defines a convex lower part and a concave upper part, an integral upstanding hollow rudder post boss formed cn the intermediate portion between its forward and rear ends, a tubular rudder post trunk secured to the upper end ofthe rudder post boss and a. rudder carrier mounted on the upper end of the rudder post trunk whereby the entire weight of the rudder and its post is transmitted directly to the stern frame structure through the trunk and rudder post'boss.

14. A spade type rudder for marine vessels of the character set forth including a rudder post having aV downwardly tapered portion and a municating therewith, said rudder frame having a transverse opening, a nut accommodated by said opening and engaging with the threaded portion of the rudder post for drawing the tapered portion of the rudder post into intimate contact with the tapered socket of the rudder frame.

15. A spade type rudder for marine vessels of the character set forth including a rudder frame extending downwardly from the top of the rudder to a point below the horizontal center of the rudder, said rudder frame having a transverse opening, a vertically apertured portion above said opening communicating therewith and a superposed downwardly tapered socket at the upper end of said rudder frame; and a rudder post having a lower portion tapered to fit the tapered socket and having a lower terminal protruding through the vertically apertured portion and threaded to receive a nut received by the transverse opening and bearing against the underside of the vertically apertured portion to draw the tapered part of the rudder post into the tapered socket. l

16. In a stern structure for vessels of the character set forth, a stern frame including a cast upper section comprising an intermediate rearwardly and upwardly inclined portion, a downwardly directed terminal at the forward end of said portion and an upstanding portion at the aft end of said intermediate portion, and an integral upstanding hollow rudder post boss formed on the intermediate portion between its forward and rear ends and terminating slightly above the normal maximum water line.

17.1n a stern structure for vessels of the character set forth, a stern frame including a cast upper section comprising an intermediate rearwardly and upwardly inclined portion, a downwardly directed terminal at the forward end of said portion and an upstanding portion at the aft end of said intermediate portion, an integral upstanding hollow rudder post boss formed on the intermediate portion between its forward and rear ends and terminating slightly above the normal maximum water line and a tubular rudder post trunk secured to the upper end of said rudder post boss.

18. In a marine vessel of the character set forth, a submerged screw propeller and an aft hull portion so contoured in the region of said propeller and with reference to which aft hull portion the propeller is so located, that when the ship attains its normal running speed, converging vertical waterplane flow lines are developed by said aft hull portion contour, which waterplane ow lines intersect at the fore and aft center of the propeller.

MICHAEL J. HANLON. 

